1. Field of the Invention
The present invention relates to a light emitter, and particularly to an LED light emitter including a light emitting diode (LED) chip and a heat sink holder, and as well as a method for manufacturing the same.
2. Related Art
As shown in FIG. 1, a conventional LED light emitter 1, in general, comprises a heat sink 11 having a recess 111 for dissipating heat, an LED chip 12 provided in the recess 111 for emitting light by photoemission, a connecting portion 13 (using the conducting paste, but the thermal conductivity coefficient of the paste is low) between a bottom of the recess 111 and the LED chip 12 for gluing the LED chip 12, and a transparent stuffing portion 14 stuffing the recess 111 for isolating the LED chip 12.
An electrode 121 connecting with the LED chip 12 electrically connects with an electrical connection wire (not shown) of an external circuit for providing the LED chip 12 with power. The most of light emitted by the LED chip 12 directly passes through the stuffing portion 14 to surroundings, and the little of light emitted by the LED chip 12 is reflected by sides of the recess 111 and passes through the stuffing portion 14. Heat generated by the LED chip 12 is let out through the connecting portion 13 and the heat sink holder 11, therefore avoiding heat within the LED chip 12 to influence recombination of electrons and holes, and shortening life of the light emitter 1.
The light emitter 1 is manufactured as follows. An LED chip 12 is provided firstly. The LED chip 12 and the connecting portion 13 are glued to the recess 111 of the heat sink holder 11. The stuffing portion 14 is filled in the recess 111.
The light emitter 1 is basically able to meet contemporary need. Its manufacture process is able to come into reality thanks to long-term semiconductor manufacturing and packaging, as well. But people are still endeavor to study and improve the light emitter 1. Such designs are shown in Taiwan Patent Nos. 095104637 and 095106043. The patent No. 095104637 discloses an insulted base between a substrate and a connecting portion for enhancing light luminance. The patent No. 095106043 discloses a static discharge prevention element packaged in an LED and a method for manufacturing it.
However, the conventional light emitter 1 includes an LED chip 12 glued by a connecting portion 13. Thermal conduction is subject to different thermal conduction coefficients of different layers and interfaces, and influences light emission and lifespan of the light emitter 1. On the other hand, during the connecting portion 13 is glued to the LED chip 12, the connecting portion 13 is apt to form voids because of piling and pressing, thus destroying interface of thermal conduction, seriously influencing heat dissipation of the light emitter 1, and shortening its life.
WIPO patent application No. WO2006112356A1 and Japanese patent application No. JP2006339542A both disclose a die directly bonded on a thermal circuit board for heat dissipation. However, this method requires material good at heat dissipation. Moreover, thermal size is just the contact size of the die, obstructing reduction of thermal resistance.
An LED light emitter with heat sink holder overcoming the defects above and a method for manufacturing it are desired.